1. Field of the Invention
The present invention is related to the field of compression and storage of compressed air. More particularly, the invention is applied to bicycles by using the pedaling motion for compressing and storing the compressed air for subsequent use.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
In a known way, the inflation of the inner tube of the wheels of a bicycle is carried out manually by pumping using a pump in the form of a piston. This operation is time-consuming and physically strenuous. In order to facilitate this inflation operation, cartridges containing compressed air permit to inflate quickly and effortlessly the inner tube. However, once emptied, the cartridge becomes unusable until it is recharged or replaced.
Based on this observation, it was devised to use the pedaling motion when using the bicycle in order to compress and store compressed air, which will subsequently be used for inflating the inner tubes.
A solution that was contemplated consisted in using the very frame of the bicycle, comprised of hollow tubes welded together, in order to form compressed-air tanks. FR 2624085 and FR 459 989 disclose the use of at least one segment of a tube forming the frame, which is made tight in order to serve as a compressed-air tank. This segment is provided with an aperture, in which is mounted a valve permitting to fill and extract compressed air. Furthermore, a pressure gauge can be mounted at the level of this segment, in order to indicate the pressure and thus the amount of air contained in this tank.
The major drawback of this solution lies in the filling of the frame, which must be performed by an external air-compression system. In addition, the frame must be entirely dedicated to this purpose and is therefore not compatible with all types of bicycle.
WO 96/22216 tries to cope with this drawback by adding air-compression means actuated by pedaling, yet in order to fill an airtight container formed of part of the bicycle frame. More particularly, the compression means are formed of one single piston hinged with the crank set of the bicycle, forming a cam according to a mechanical crank system, so as to convert the rotation of the crank set into a translational motion of said piston, in order to fill the integrated tank.
Besides the drawback of using here too the frame as a tank, this solution raises a major technical problem: the force required to actuate the piston in order to compress the air to a sufficient pressure, higher than 10 bars (1,000,000 Pa), is too high and therefore creates too much resistance to the pedaling for the cyclist. In addition, such a compression force would require a piston with a too large length or a too large diameter. Finally, the compression forces would result into too high thermal stress, in particular into a heating of the piston likely to damage and burn the user.
EP 0507007 discloses yet another air-compression system using the rotation of the crank set to actuate a piston and to fill a compressed-air tank, but for serving as pneumatic power in order to facilitate the pedaling motion, namely on an upward slope. The single piston raises the same problems as described above, making this kind of system technically unfeasible.